The present invention is directed to the fabrication of a lithium ion-conducting electrolyte material.
Phthalocyanine was discovered during investigation of a blue material formed as a by-product in the commercial preparation of phthalimide. The substance was found to contain iron held in the center of a heterocyclic macro-ring. Further investigation revealed that other metals could replace iron. The most direct synthesis consists of heating phthalonitrile with a metal. The discovery led to many commercial dyes and pigments.
In recent years, several materials have been proposed for laser addressed applications in which laser beams are used to scan across the surface of the material to leave a written impression thereon. Metal and metal-free phthalocyanines have been used as infra-red absorbing dyes for a number of applications. These phthalocyanines contain from 5 to 16 peripheral organic substituent groups that are linked to the phthalocyanine through sulphur, selenium, tellurium, or nitrogen atoms. Harrison et al, U.S. Pat. No. 5,618,929, issued Apr. 8, 1997, disclose substituted phthalocyanines which absorb infra-red radiation. In another field of use, Moussavi, U.S. Pat. No. 5,112,597, issued May 12, 1992, discloses that lithium phthalocyanine is useful for in vivo oxygen determination by EPR spectrometry.
I have found that lithium phthalocyanines are useful in electrolytes for electrochemical cells.
Ion conducting polymer electrolytes with ionic conductivities on the order of 10.sup.-3 S/cm at ambient temperatures have been prepared by incorporating non-aqueous liquid electrolytes into polymer matrices. For example, in a lithium cell, the anion of the lithium salt is bonded to the polymer matrix thus resulting in single ionic conductivity upon dissociation of the salt in the non-aqueous media. Because of the presence of volatile organic plasticizers (non-aqueous liquid) these electrolytes suffer from poor dimensional and thermal stability. In addition they are very susceptible to degradation through corrosion/passivation reactions with lithium metal electrodes. Thus, it is desirable to improve the operating characteristics of electrolytes and to overcome these and other operational limitations inherent in electrochemical devices. One way of overcoming the limitations of the materials currently used in the electrochemical art is to develop and investigate new materials for their potential application in electrochemical cells.
Accordingly, it is an object of the present invention to provide novel lithium ion-conducting materials which can be used as an electrolyte.
Other objects and advantages of the present invention will be apparent to those skilled in the art.